Looks like I forgot updating this Froum for a while. ;-( Sorry for that.
Those were no serios bugs, but probably it's worth an update.

The change log:

// Release 1.2.6

// 25.10.07
More Debugging information

// 17.10.07
Removed dependency of mb_detect_encoding

// RELEASE 1.2.5

// 12.10.07
Bug: Empty unsubscribe mail was sent. (Thanks to Björn)
Bug: French translations didn't really work. Should be fixed now.
Moved Mailfix into it's own Plugin: http://wordpress.org/extend/plugins/wordpress-22-mailfix/
Bug: Typos in German translation.

// 11.10.07
Fixed problem with profile checking.

// RELEASE 1.2.4

// 07.10.07
Added change log to admin panel
Moved mailfix into the post_notification dir, to make the installation easier.
Small adjustment in the install.php: Only load install-helper.php it it needed - didn't solve the problem, but does no harm.
Also had some trouble with the svn-dir. This should be solved now.
Fixed some bugs in the documentation.

// 05.10.07
Some variable cleanup in the frontend.php after the last bug fix. Nothing serious.

// RELEASE 1.2.3

// 05.10.07
Bug: Errors were not printed in the front end.

// RELEASE 1.2.2

// 02.10.07
Removed some warnings.
Removed possible Bug when subscribing.
Removed some small bugs which PHP fixed by itself.